Max Size: 10cm

Assam Danio (Devario assamensis)

Assam Danios are active, reasonably hardy and friendly fish making them an excellent addition to a peaceful community aquarium, especially if you already keep larger species. However, these Danios are among the biggest and require a large aquarium with plenty of swimming space. These Danios prefer cooler temperatures and do not have specific needs when it comes to water parameters, so they are suitable for the beginner aquarist, providing they have a large enough aquarium.

Assam Danios are a shoaling species in nature; therefore, it would be better to maintain them in groups of six or more individuals. Keeping these fish in more significant numbers will not only help to contain any aggression towards other inhabitants as the fish will be concentrating on maintaining their hierarchical rank within the group, but the males will also exhibit better colours in the presence of rival males.

Suitable tankmates for these Danios could include medium to large-sized Danios, Characins, Barbs and Rasboras, as well as peaceful Cichlids, Catfish, and Loaches. However, it would be better to avoid smaller species as they may be seen as a snack or slow-moving species as they may feel nervous around these active fish.

The ideal aquarium setup for these Danios would be one that resembles a flowing river or stream with a substrate of smooth rocks or boulders and some fine gravel or sand. You can further furnish the aquarium with driftwood roots or branches and some hardy aquatic plants such as Bolbitis, Anubias or Microsorum.

The aquarium will need to be well oxygenated and have a reasonable flow rate as these fish will enjoy swimming against the current; therefore, adding a powerhead or an internal filter would be ideal.

Since these Danios naturally occur in pristine habitats, they are intolerant to the buildup of excessive organic waste. Therefore these fish require good water conditions to thrive, and you should never introduce them into a biologically immature aquarium. In addition, the aquarium will need a tight-fitting lid as these Danios are accomplished jumpers.

The Assam Danio has a yellowish-green body and a white abdomen. They possess two wide longitudinal reddish-orange stripes above the lateral line and two broken orangy-red stripes along their sides. These Danios have large mouths and eyes, and their caudal fin is forked. In addition, their pectoral, pelvic and anal fins are transparent; the caudal fin is reddish, and their dorsal fin is pinkish.

Tank Mates for the Assam Danio

1 ideal tank mate ideas for the Assam Danio include:

Dwarf Gourami(Trichogaster lalius)
Quick Facts
Scientific NameDevario assamensis
Year Described1984
Other NamesAssamese Danio
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 6+
Lifespan4 - 8 years
Water Parameters
Water TypeFreshwater
PH6.0 - 8.0
GH5 - 15
TDS36 - 215
59 - 71℉
15 - 21.7℃

Photos of the Assam Danio

Assam Danio
Assam Danio

Natural Habitat

Assam Danios are endemic to the tributaries of Lake Mirik and the Mahananda River in West Bengal, as well as the Kalmoni river drainage in Assam. You can also find them in the lower Brahmaputra River System in India in South Asia.

These Danios live in both lowland and higher altitude regions where they inhabit moderately flowing clear, well-oxygenated waters in pools, streams and rivers. Their habitats comprise gravel and different-sized rocks for substrate and have overhanging vegetation as well as some marginal vegetation.

What to feed the Assam Danio

Assam Danios are not finicky eaters in the aquarium. However, a good quality dried product should be used as the staple diet alongside frequent meals of frozen, live and freeze-dried foods such as cyclops, mosquito larvae, chopped earthworms, brine shrimp, daphnia and bloodworm. Providing your Danios with a varied diet will help your fish preserve their best colours and condition. It would be beneficial for your Danios if you also gave them vegetable flakes occasionally to provide a well-balanced diet.

How to sex the Assam Danio

It can be relatively hard to differentiate between male and female Assam Danios; however, the females are slightly larger than males, possess a more rounded abdomen and are duller than males. In contrast, males are usually smaller, slimmer, and more vibrantly coloured than females.

How to breed the Assam Danio

Assam Danios are egg-scatterers that exhibit no parental care. When these Danios are in good condition, they will often spawn, and in a densely-planted, well-established aquarium, small numbers of fry may start to appear without interference. However, if you would like to improve the quantity of fry, a more controlled approach will be needed.

You can condition your adult group together; however, you need to set up a separate breeding tank and half-fill it with mature water. It would be best if you filled much of the available space with suitable spawning mediums such as java moss or spawning mops, or you could place mesh, pebbles or marbles on the base of the tank so the eggs can fall through and be hidden.

Their water will need to be somewhat acidic to neutral with a slightly higher temperature than average. You should also add an air stone or an air-powered sponge filter to provide water movement and oxygenation. Once you have conditioned the adult fish and the female's stomach is full of eggs, you should introduce one or two pairs into the breeding tank. Feeding your Danios with small amounts of live and frozen food can activate spawning, and numerous spawning events will probably occur before a female has run out of eggs.

Spawning usually takes place within 24 hours, with the female being noticeably slimmer once all her eggs have been laid; then, after 48 hours, you should vacate the adults, so they do not consume the eggs.

The Incubation period can be temperature-dependent but typically takes between 24 and 36 hours for the fry to hatch. The fry will then start to swim freely a few days after that.

It would be best if you initially fed your fry on liquid fry food, Paramecium, or powdered food, moving on to newly hatched brine shrimp and microworms around a week or so later once they are big enough to accept them.

Other Danios of interest

Barred Danio(Devario pathirana)
Bengal Danio(Devario devario)
Black Barred Danio(Danio absconditus)
Blood Tailed Danio(Devario annandalei)
Blue Danio(Danio kerri)
Celestial Pearl Danio(Danio margaritatus)
View all Danios
Date Added: 03/03/2022 14:16:12 - Updated: 03/03/2022 14:37:24